From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758781Ab3IBJCM (ORCPT ); Mon, 2 Sep 2013 05:02:12 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:37834 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758524Ab3IBIzh (ORCPT ); Mon, 2 Sep 2013 04:55:37 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: David Vrabel , Konrad Rzeszutek Wilk , Luis Henriques Subject: [PATCH 43/58] xen/events: initialize local per-cpu mask for all possible events Date: Mon, 2 Sep 2013 09:54:28 +0100 Message-Id: <1378112083-9475-44-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1378112083-9475-1-git-send-email-luis.henriques@canonical.com> References: <1378112083-9475-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.5.7.21 -stable review patch. If anyone has any objections, please let me know. ------------------ From: David Vrabel commit 84ca7a8e45dafb49cd5ca90a343ba033e2885c17 upstream. The sizeof() argument in init_evtchn_cpu_bindings() is incorrect resulting in only the first 64 (or 32 in 32-bit guests) ports having their bindings being initialized to VCPU 0. In most cases this does not cause a problem as request_irq() will set the irq affinity which will set the correct local per-cpu mask. However, if the request_irq() is called on a VCPU other than 0, there is a window between the unmasking of the event and the affinity being set were an event may be lost because it is not locally unmasked on any VCPU. If request_irq() is called on VCPU 0 then local irqs are disabled during the window and the race does not occur. Fix this by initializing all NR_EVENT_CHANNEL bits in the local per-cpu masks. Signed-off-by: David Vrabel Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Luis Henriques --- drivers/xen/events.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/xen/events.c b/drivers/xen/events.c index b5b559a..025e98b 100644 --- a/drivers/xen/events.c +++ b/drivers/xen/events.c @@ -324,7 +324,7 @@ static void init_evtchn_cpu_bindings(void) for_each_possible_cpu(i) memset(per_cpu(cpu_evtchn_mask, i), - (i == 0) ? ~0 : 0, sizeof(*per_cpu(cpu_evtchn_mask, i))); + (i == 0) ? ~0 : 0, NR_EVENT_CHANNELS/8); } static inline void clear_evtchn(int port) -- 1.8.3.2